FIELD OF THE INVENTION
The present invention generally relates to a mold for forming a housing of a card edge connector and a housing obtained by the mold.
A housing of a card edge connector, for example, a DIMM (Dual In-Line Memory Module) connector or an advanced RIMM (Rambus Interface Memory Module) connector, has an elongate body defining a central slot for receiving a lower side of a memory module. A number of pairs of contact passageways are defined in the housing beside the central slot for receiving corresponding contacts which have contact portions extending into the slot to electrically engage with the memory module inserted into the connector. To help the memory module to be correctly inserted into the connector, two towers each defining a guiding groove are formed at two lateral ends of the elongate body of the housing. To help the memory module to be securely received by the connector and easily ejected from connector, two ejectors each having a latch about its upper end and a kicker about its lower end are pivotably mounted in the towers.
To form the contact passageways, a mold for forming the housing by plastics injection molding needs a number of core pins mounted in a mold cavity of the mold in a cantilevered manner. Each core pin has a thin cross section along a longitudinal direction of the mold cavity. Furthermore, to help the major faces of the body of the housing to be integral and aesthetic, a gate of the mold are set about a lateral end face of one of the towers which causes the plastics injection needing to be under a large pressure whereby the plastics can flow through a space of the mold cavity for forming the elongate body to fill a space for forming the opposite tower. In combination of the factors of the large injection pressure and the thin cross section of the core pins, the core pins located near the gate of the mold become easily deflected or dislocated when the injection pressure fluctuates. The deflected or dislocated core pins cause the formed corresponding contact passageways to be irregular in shape, whereby when the corresponding contacts are received in the contact passageways, the contacts deviate from their true positions. Thus, the connector cannot have a precise electrical connection, with the memory module, resulting in a poor electronic data transmission between the two devices.
Hence, an improved mold for forming a housing of a card edge connector is needed to eliminate the above mentioned defects of current art.